I live for the CABE

Every seat I've torn apart to clean, fix, etc. has always had a left and a right spring. Make sure when you put it back together that you have the right one on the right side. PM if you don't know how to tell. Also, a tip I learned, is to set the "preload" (inside) the spring nut at equal distances from the end of the threaded area, usually, a measurement of 3/4" or so is a good place to start. If the nut is uneven in that area, one side of the rear of the seat will set higher and look bad. Also, the preload is important to the function and integrity of the spring working, but not too much and giving it a no-bounce at all feel.